Studies will be undertaken to establish some basic properties of the autoantiidiotype antibody response. The primary objective is to gain a more thorough understanding of this potentially important control mechanism and apply the knowledge to naturally occurring immune processes. The normal production of autoantiidiotypic antibodies will be assayed following antigen stimulation using radioimmunoassay techniques. Inbred mice, inbred rabbits and outbred rabbits will be studied. The genetics of idiotype production will be studied using the autoantiidiotype reagents. The genetic studies will be used as a basis to study the maternal transfer of autoantiidiotypic antibodies of offspring and subsequent effects on the developing immune system of the mature offspring. The use of inbred lines of rabbits and mice will allow precise control of many variables not controllable in outbred populations and will provide models for approaches to application of knowledge gained into potential clinical application. Ultimately, translation of these data into clinical applications may include tumor immunity (autoregulation of "blocking antibodies"), transplantation immunity and pathological conditions presumably mediated by autoimmune processes such as acquired hemolytic anemia, systemic lupus erythematosus, Hashimoto's disease and pernicious anemia.